If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

With the spec, you can also double check your mother board maker to see if that specific chip is supported.

If you don't find the answer with those two, please post back your motherboard manufacturer and version(s) so the pair (mb & cpu) can be looked at for issue.

I would suspect an older PC and maybe a bios update for the bios to handle the processor better, if at all. Other thoughts would be SpeedStep issues (try turning off / disabling in bios) which again would point back to the bios.

one of those spec codes to the right on that page (or at the end of the URL) If not one of those, then that maybe the problem.

*If* after disabling the speedstep it shows only 2.4 ... then the 1.2/2.4 reading would be normal ... showing you the range of speeds it could run. The idea being if your just browsing through email and web, you don't need 2.4 GHz speed (and conversely the heat and energy it uses) .... but when you go to do more serious work or try to play a game, the processor shifts into higher speeds.. etc..

note the processor specs above mention *Enhanced* Speedstep where this processor doesn't have the "Enhanced" version it has the oringinal speedstep techology.

Last edited by TG2; January 14th, 2011 at 11:24 PM.
Reason: additional content

OK, I would date this machine as being in or around 2001/2 technology. It supports SDRAM PC133 memory.

This was early days for the Intel P4, and performance rigs used RAMBUS RDRAM, which I can remember costing £1,000 (GBP) for 1GB !!!!!

HP brought out this range of office desktops to use the much cheaper SDRAM.

Basically, I don't think that the CPU is supported by the MoBo/BIOS, and the system is reverting to "failsafe" settings.

You say that the BIOS won't let you alter the settings , so I suppose that the multiplier is fixed?

So, I think that you have supported data BUS speeds of 100 and 133MHz, and a fixed multiplier of 12x (generally, machines that support PC133 RAM will also support PC100)

100 x 12 = 1.2GHz
133 x 12 = 1.596GHz

I know that model of HP was available with a P4 1.6GHz processor, which would be supported. The P4 2.4GHz is probably looking for DDRAM memory:

266 x 9 = 2.394GHz

So I very much doubt if a BIOS update will help, unless it supported a multiplier of 18x.

I have an AMD Athlon XP1900+ of around the same era. The BIOS has two global settings that are basically for reliability or performance. If I select performance I get 1.596GHz, and if I select reliability I get 1.2GHz. The processor's actual clock speed is supposed to be 1.6GHz.

In this case Windows XP Pro SP3 shows it as an Athlon XP 1.2GHz, with no range. I believe that Windows gets its information from the BIOS, which in my case would be correct, as the BIOS is set to run at 1.2GHz.

In your case, I suspect that the BIOS is telling Windows that it has a 2.4GHz processor that it can only run at 1.2GHz............although I must admit that is the first time I have seen a Windows screen like that.

You might like to check the HP site to see if there is a BIOS revision that supports faster processors, but please be very careful!

notice the first result (not the ad) is for a Tech Reference.. though for the French business unit (its in english) it confirms that the dips mentioned are "reserved" with 5 thru 10 for bios clear and emergency (crisis) recovery and bios flash protection.

without knowing the details on the CPU ... spec code printed on the chip itself, it becomes the only thing that would be of question. The system was designed to give a 400MHz FSB and the only processor I could find by the hunt & peck method looks like it would work all else being "ok".

Also on the support page for the system at HP, its hard to say if you have a newer bios or there is one.. HP lists the version they have as JA.01.04 -- 7 May 2002 while the CPUZ gives your bios as JA.01.07US and 7/19/2001 ...

IF you're going to try the other bios .. see if the utility allows you to take a backup of your current bios ... so that you can revert to it if needed.

Part of the confusion is in not knowing which VL420 you have.. the one that comes up immediately is the MidTower ... though the same board was listed for all three, that's not always the case... and reading here... http://h20000.www2.hp.com/bizsupport...5&mode=4&idx=0

suggests that each change of bios included additional options for support of higher processors or corrections to the support

Sorry, but you have the wrong 2.4Ghz processor..

The "SL & WF" There is a P4 2.4 cpu that is spec SL6WF ... and that processor would match the rest of your numbers ... 2.4 GHz ... 512 cache, 800 ...

The first part ... easy to recognize 2.4GHz ... that's the CPU running frequency. The second part of the number 512 ... is the amount of "L2" Cache memory .. the third part of the number 800 ... means 800MHz Front Side Bus (FSB)

Your system board is not capable of generating an 800MHz FSB, its only able to do 400MHz.

You need 2.4/xxx/400 I put XXX because they make 1024 (1 meg) cache P4's, they also make 512k and 256k cache models too.

and if you follow one of the SL numbers in the first "Northwood" section (like SL65R .. and not the second northwood, thats the Pentium 4 HT section)... you'll get to Intel's ARK pagehttp://ark.intel.com/Product.aspx?spec=SL65R
and again on the right side you'll see there's a bunch of processors that are similar in specs...

See if the reseller you purchased the processor from is willing to take the CPU back in trade for one of the correct model (400MHz FSB) ... if not, you'll probably want to list it on Ebay or some such, and then will need to order the correct model CPU for your system board (400MHz Front Side Bus)

Last edited by TG2; January 16th, 2011 at 07:52 PM.
Reason: minor correction

thanks for the help guys.. yeah TG it was a 6... I didn't wipe the thermal grease off good enough, but yeah i bought it on amazon only paid 10 bucks for it so no loss there... Thanks again everyone...

10! wow... been a while ... I'm in the AMD camp personally ... and usually on low budget so when the time comes that I can upgrade its usually too late to get good prices ... like Nihil was saying.. PC3200

... when I finally wanted to get some, it was 100 bucks for a gig, and at that time PC2 memory was only 30 bucks a gig.. ahhh the upgrade bug...

I see there are a few Celeron 2.4/128k/400's for 3.95 at amazon.. LOL costs more to ship at that price..